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Old 22nd August 2011 | 23:21
  #3165 (permalink)  
DozyWannabe
 
Joined: Jul 2002
Posts: 3,093
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From: UK
Originally Posted by safetypee
A stick pusher is not installed to prevent a stall, it is a recovery device.
True. Read your HTBJ to get the background. A basic "stick nudger" was installed in all UK CAA certified 707s due to the less than benign characteristics of that airliner at the stall, and a full stick push was installed in all CAA-certified T-tail airliners because of the deep-stall characteristic inherent in that design (which was illustrated by pancaked 1-11s and Tridents that fell foul of it). I can't remember off the top of my head if one was installed on CAA-certified 747s, but Davies does mention that the stall characteristics are surprisingly benign, and that the aircraft tries to get it's nose down without significant assistance. Judging by the traces, it would appear that the A330 is equally benign, as long as one doesn't hammer the THS to the nose-up stop.

Now - as I said, I don't care about blame, I don't care about legal bobbins (though I hope that the victims families are properly compensated at the end of all of this), but what it ultimately boils down to for me is that it is unacceptable to induce a nose-up attitude of that magnitude (or make any control inputs as large as the PF was making) in the cruise phase of flight. None of your "but the THS should have...", "Why did the autopilot kick out...", "What if the displays were confusing..." matters as far as I'm concerned. If a pilot is expected to handle the aircraft in the cruise phase then he should damn well be trained to handle the aircraft in the cruise phase - automatically, manually, on the trim dials if necessary - and if airlines have been neglecting the training to do so then we have serious problems here.

@exeng - I'm well aware, but I'm also aware that there comes a time when the potential outcry forces manufacturers and/or airlines to listen. The DC-10 crash in Ermnonville was one such time. The A330 test crash which killed senior test pilot Nick Warner was another. Heaven knows it must be a lonely place when you believe that you're the only one sticking your head above the parapet, but that's the point at which you must band together and draw a line in the proverbial sand. We've had one accident where the pilots were so damned tired that they stalled their aircraft and maintained the controls in a stall-inducing attitude until it hit the ground. It now appears that we have a transatlantic flight where the designated pilot in charge seemed to have no idea how to control the thing manually at altitude. Eventually something has got to give. Right now, public faith in the methods of the finance industry and the methods it employs is at an all-time low - with enough pressure you could have the beancounters on the ropes. I'm not saying it will be easy, but if it was ever possible it has to be possible now.

@testpanel (below) - Forgive the guy his wording, which was slightly inaccurate - his point is fairly valid though. They may not have a stick-shaker, but they do have an aural warning and if I recall correctly the word "STALL" flashing in large letters in the centre of the ADI display of the PFD. As such it isn't likely that the annunciations could have been missed (for nearly a minute) unless there was something terribly wrong with either the systems (which the CVR and FDR apparently refute), or the perception of the crew.

Last edited by DozyWannabe; 23rd August 2011 at 00:51.
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